completely new: how exactly do uniques work?

Hi all,

I have been following a guide lately after I was struggleing a bit and this guide did recommend getting a certain unique chest piece.

I play a minion witch and the chest piece is the Enfolding Dawn Pilgerin Vestments, that do give +100 spirit.  

I thought, when you get a unique, it is overall "better" than the normal, magic or rare items, like it is in other games, but it seems to that uniques in this game just merely alter how you play the game?

The thing is: I have a rare yellow chest piece, that has more perks. It's item lvl 53 and it has 200 more shield but gives me over 1k more shield due to the perks on it, doubles my mana and mana recharge rate.

The unique item is item lvl 80ish and gives me +100 spirit and I think 8% more elemental res.

With those 100 spirit more I basically only can equip 2 more fire minions.

While it is nice to have 4 instead of 2 minions on a minion build I kind of feel super let down by how "unexciting" this unique is.

Same goes for the uniques I've found myself in the game already, like, I quickly check stats if there is ANYTHING special on them and then just delete them to get gems for orbs.

...and then, you can't seem to upgrade uniques either like you can rares, so get they get more perks?

What am I missing here?

Uniques run quite the spectrum in path of exile 1 and 2. Some are basically just twink gear, others are 'neat' collector's item that don't seem to have much use (looking at you, fire quarterstaff). Others have unique mechanics that become the cornerstone of builds, such as the helmet Three Dragon's which allows your lightning damage to freeze. Then there are the 'chase uniques' which come from the uber bosses which are VERY powerful.

They're fun to collect, however useful they are.

As for upgrading uniques: At the moment you can increase their quality and sockets like you can normal items irrc. You can also corrupt them with a Vaal orb like you can normal items, which might add an additional modifier if you're lucky. But otherwise, they are what they are.

GGG has always had the philosophy that the best general endgame items should be rare items, because there's a range of affixes on them, and getting an absolutely perfect lategame rare for an item slot is potentially a week-spanning endeavour.

As above, they may ofter build-defining affixes that you can't get another way, and in the past, uniques have often paved the way for new playstyles that then found their way into new skillgems or nodes on the passive tree. But you'll always pay for that what you're not getting instead.